Fix handling of default formal parameters in DeclarationResolver.

pkg/analyzer/lib/src/generated/declaration_resolver.dart

Index: pkg/analyzer/lib/src/generated/declaration_resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/declaration_resolver.dart b/pkg/analyzer/lib/src/generated/declaration_resolver.dart
index a6b8a13998ffd5d4175153e82cf82a8dc4fe2a7d..df4afc29c81429b4694dc568b16cac26f826441c 100644
--- a/pkg/analyzer/lib/src/generated/declaration_resolver.dart
+++ b/pkg/analyzer/lib/src/generated/declaration_resolver.dart
@@ -126,7 +126,7 @@ class DeclarationResolver extends RecursiveAstVisitor<Object> {
       });
     }
     _walk(new ElementWalker.forParameter(element), () {
-      super.visitDefaultFormalParameter(node);
+      node.parameter.accept(this);
     });
     _resolveMetadata(node, node.metadata, element);
     return null;